October 29, 2007

 

Cattle industry has a new way to maximise feed efficiency

 

 

The Southwest Centre's Field Day has unveiled a new method of calculating feed utilisation. The method is called Residual Feed Intake, or RFI.

 

Eldon Cole, livestock specialist with University of Missouri Extension, said RFI is measuring feed efficiency or conversion and will be the basis for new beef and forage project.

 

A group of 89 Angus X Simmental heifers will make up the initial herd at the research facility. These same cattle were in Columbia earlier this summer being "phenotyped," or measured for their daily feed intake and gain.

 

This process identified those heifers that were more efficient and those less efficient based on their RFI numbers.

 

The phenotyping process required individual daily feed intake to be measured for about 70 days. Then, based on the feed intake, gain and body weights, the RFI is calculated comparing each heifer to the average expected intakes.

 

A negative value indicates they ate less feed than the average of the group yet gained the same weight.

 

The RFI is rated as a moderately heritable trait similar to growth and some carcass traits.

 

Even though these heifers were tested on a concentrate diet, the RFI will pick out the efficiency differences on pasture and hay similarly, said Cole.

 

Feed costs in the feedlot and land costs to produce forage for cattle make up two-thirds of the production costs of beef cattle. It is hoped this project will focus attention on efficient production of beef cattle on a variety of forages used in southwest Missouri.

 

Since the individual animal feed monitoring system is expensive, most of the practical use of RFI at this time will come from bull evaluation stations. This data may ultimately be converted into expected progeny difference values, according to Cole.

 

During the field day, the best 10 head and the poorest 10 head based on RFI were on display. Visually the heifers were similar.

 

The top 10 during the test had gained 3.1 pounds per day on 17.6 pounds of feed.

 

In contrast, the low 10 had gained 3.2 pounds per day while eating 24.9 pounds per day.

 

The 69 in-between heifers ate 22.9 pounds per day while gaining 3.3 pounds.

 

The most efficient heifers ate 25 to 30 percent less feed than the low end of the group.

 

Cole said this difference offers a lot of potential for feed savings in the future for the beef industry.

 

The project at the Southwest Research Centre is a long-term endeavour and the most efficient heifers will be bred starting this fall to efficient bulls. The lower efficiency heifers will be bred to poor RFI bulls.